Aromatherapy is a form of alternative medicine that uses volatile plant materials, known as essential oils, and other aromatic compounds for the purpose of altering a person’s mind, mood, cognitive function or health.
Some essential oils such as tea tree have demonstrated anti-microbial effects, but there is still a lack of clinical evidence demonstrating efficacy against bacterial, fungal, or viral infections. Evidence for the efficacy of aromatherapy in treating medical conditions remains poor, with a particular lack of studies employing rigorous methodology, but some evidence exists that essential oils may have therapeutic potential.
Modes of application
The modes of application of aromatherapy include:
- Aerial diffusion: for environmental fragrance or aerial disinfection
- Direct inhalation: for respiratory disinfection, decongestant, expectoration as well as psychological effects
- Topical applications: for general massage, baths, compresses, therapeutic skin care
Some of the materials employed include:
- Essential oils: Fragrant oils extracted from plants chiefly through steam distillation (e.g., eucalyptus oil) or expression (grapefruit oil). However, the term is also occasionally used to describe fragrant oils extracted from plant material by anysolvent extraction. This material includes incense reed diff-users.
- Absolutes: Fragrant oils extracted primarily from flowers or delicate plant tissues through solvent or super-critical fluid extraction (e.g., rose absolute). The term is also used to describe oils extracted from fragrant butters, concretes, and enfleurage pomades using ethanol.
- Carrier oils: Typically oily plant base triacylglycerides that dilute essential oils for use on the skin (e.g., sweet almond oil).
- Herbal distillates or hydrosols: The aqueous by-products of the distillation process (e.g., rosewater). There are many herbs that make herbal distillates and they have culinary uses, medicinal uses and skin care uses. Common herbal distillates are chamomile, rose, and lemon balm.
- Infusions: Aqueous extracts of various plant material (e.g., infusion of chamomile).
- Phytoncides: Various volatile organic compounds from plants that kill microbes. Many terpene-based fragrant oils and sulfuric compounds from plants in the genus “Allium” are phytoncides , though the latter are likely less commonly used in aromatherapy due to their disagreeable odors.
- Vaporizer (Volatized) raw herbs: Typically higher oil content plant based materials dried, crushed, and heated to extract and inhale the aromatic oil vapors in a direct inhalation modality.Some benefits that have been linked to aromatherapy, such as relaxation and clarity of mind, may arise from the placebo effectrather than from any actual physiological effect. The consensus among most medical professionals is that while some aromas have demonstrated effects on mood and relaxation and may have related benefits for patients, there is currently insufficient evidence to support the claims made for aromatherapy. Scientific research on the cause and effects of aromatherapy is limited, although in vitro testing has revealed some antibacterial and antiviral effects. There is no evidence of any long-term results from an aromatherapy massage other than the pleasure achieved from a pleasant-smelling massage. A few double blind studies in the field of clinical psychology relating to the treatment of severe dementia have been published. Essential oils have a demonstrated efficacy in dental mouthwash products.
Aromatherapy has been promoted for its ability to fight cancer; however, according to the American Cancer Society, “available scientific evidence does not support claims that aromatherapy is effective in preventing or treating cancer”.
In addition, there are potential safety concerns. Because essential oils are highly concentrated they can irritate the skin when used in undiluted form.Therefore, they are normally diluted with a carrier oil for topical application, such as jojoba oil, olive oil, or coconut oil. Phototoxic reactions may occur with citrus peel oils such as lemon or lime. Also, many essential oils have chemical components that are sensitisers (meaning that they will, after a number of uses, cause reactions on the skin, and more so in the rest of the body). Some of the chemical allergies could even be caused by pesticides, if the original plants are cultivated. Some oils can be toxic to some domestic animals, with cats being particularly prone.
Two common oils, lavender and tea tree, have been implicated in causing gynaecomastia, an abnormal breast tissue growth, in prepubescent boys, although the report which cites this potential issue is based on observations of only three boys (and so is not a scientific study), and two of those boys were significantly above average in weight for their age, thus already prone to gynaecomastia. A child hormone specialist at the University of Cambridge claimed “… these oils can mimicestrogens” and “people should be a little bit careful about using these products. The study has been criticized on many different levels by many authorities. The Aromatherapy Trade Council of the UK has issued a rebuttal. The Australian Tea Tree Association, a group that promotes the interests of Australian tea tree oil producers, exporters and manufacturers issued a letter that questioned the study and called on the New England Journal of Medicine for a retraction (ATTIA). The New England Journal of Medicine has so far not replied and has not retracted the study.
As with any bio active substance, an essential oil that may be safe for the general public could still pose hazards for pregnant and lactating women.
While some advocate the ingestion of essential oils for therapeutic purposes, licensed aromatherapy professionals do not recommend self prescription due the highly toxic nature of some essential oils. Some very common oils like Eucalyptus are extremely toxic when taken internally. Doses as low as one teaspoon have been reported to cause clinically significant symptoms and severe poisoning can occur after ingestion of 4 to 5 ml. A few reported cases of toxic reactions like liver damage and seizures have occurred after ingestion of sage, hyssop, thuja, and cedar. Accidental ingestion may happen when oils are not kept out of reach of children.
Oils both ingested and applied to the skin can potentially have negative interaction with conventional medicine. For example, the topical use of methyl salicylate heavy oils like Sweet Birch and Wintergreen may cause hemorrhaging in users taking the anticoagulant Warfarin.
Adulterated oils may also pose problems depending on the type of substance used.
In early 2014, a cat received chemical burns after he spilled the liquid from a reed diff-user.